There are certain steps for classification of plant kingdom. These step are called Taxa and is singular Tax.on. Using the steps classification is to be done ICBN or International Code of Botanical Nomenclature is the International constitution for naming the plants. Seven main. steps are recognised by ICBN. These are:
- Kingdom: The plant kingdom is composed of the whole number and types of plants present in the world. The plant kingdom is comprises of about 450000 species.
- Division: Plant Kingdom is divided into seven Divisions.
- Class: Each division is divided into several classes.
- Order: Each class is divided into several orders.
- Family: Each order is divided into several families.
- Genus: Each family is divided into several Genera (PI. of Genus).
- Species: Each genus is divided into several species.
There are about 250000 fruit producing plants. The name of the species should be written in small letters. Usually several members comprises the higher step, e.g. several species constitute a genus and several genera constitute a family etc. Sometime only one member of a Taxon may constitute a higher Taxon. In case of necessity any unit may be splitted to sub-unit for which the term sub should be prefixed against the main unit (Taxa).e.g. Sub Order, Sub-Family Sub-Genus, Sub-species etc.